Speaker
Description
Personal sound zones (PSZ) aims to create bright and dark acoustic zones within a space by filtering a reference signal to drive multiple loudspeakers. Adapting the control filters is challenging due to variations in acoustic conditions or shifts of the zones, since error microphones are assumed to be fixed in the zones and the estimated acoustic transfer functions cannot be updated.Under these constraints, a real-time adaptive filtering approach was developed for two movable sound PSZ zones. Each zone consists of five loudspeakers in front of six microphones mounted on the same frame to ensure a fixed geometry. The ten filters are implemented in the time domain to minimize latency. The filter coefficient are updated using a frequency-domain block Filtered-x Normalized Least Mean Square (FxNLMS) algorithm. The system was deployed on a real-time controller.Performance, evaluated in terms of contrast and error, was tested under varying PZS positions and changing local acoustic conditions. The results show algorithm convergence and acceptable performance. The discussion highlights fundamental advantages and limitations of the presented approach, including sensitivity to uncertain and time-varying transfer paths.